Investigation work is being continued on the integrative control of hormone secretion. Specifically the effect of lipids on hGH and HPr secretion is being examined to determine if lipids inhibit HPr secretion as they do hGH secretion. Attempts to domonstrate which hGH secretory mechanisms are blocked by lipids are also being made. In addition, studies on the effects of serotonin precursors on hGH and HPr secretion in normal subjects and those with pituitary tumors are being conducted. This proposal also calls for investigations on the effect of lithium on IRI and IRG secretion in vitro and in vivo. Methods for quantitating insulin receptors on peripheral monocytes have been set up to examine the effect of various diets on receptors. We also plan to look at receptors in various disease states. BIBLIOGRAPHIC REFERENCES: B. Bowman Brach, W.G. Blackard, and H. Rothschild. A Review of Deaths due to Inspected Lactic Acidosis at a Large Metropolitan Hospital. Southern Medical Journal 68:202, 1975. D.L. Horwitz, J.I. Starr, M.E. Mako, W.G. Blackard, and A.H. Rubenstein. Proinsulin, Insulin, and C-peptide Concentrations in Human Portal and Peripheral Blood. J. Clin. Invest. 55:1278, 1975.